Double corbel


  • The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

International Concrete Abstracts Portal


Title: Double corbel

Author(s): Tjen N. Tjhin and Daniel A. Kuchma

Publication: Special Publication

Volume: 208


Appears on pages(s): 117-128


Date: 10/29/2002

A double corbel projecting from an interior column is designed using the strut-and-tie method according to ACI 318-02 Appendix A. The corbel transfers precast beam reaction forces, Vu of 61.8 kips (275 kN) acting at 6 in. (152 mm) from the face of the column at both ends. To account for beam creep and shrinkage deformations, a factored horizontal force, Nuc of 14.3 kips (63.6 kN) is assumed to develop at each side of the corbel top. The column is 14 in. (356 mm) square. The upper column carries a factored compressive axial load, Pu of 275 kips (1223 kN). The compressive strength of concrete, fc and yield strength of steel reinforcement, fy are taken as 4 ksi (27.6 MPa) and 60 ksi (414 MPa), respectively. Normal-weight concrete is assumed. The selected dimensions including the bearing plates are shown in Fig. (3.2-2). The shear span to depth ratio, a/d, is 0.38. A simple strut-and-tie model shown in Fig. (3.2-3) was used for the design. The provided main tie reinforcement is 7 #4 (#13 mm) bars. The anchorage of these bars is provided by welding each end of the bars to a structural steel angle of 4 in. x 4 in, x 1/2 in. (102 mm x 102 mm x 13 mm). The reinforcement details are shown in Fig. (3.2-5).